| 摘要 |
The invention relates to a process for the manufacture of a cephalosporin derivative of the formula I: <IMAGE> I in which X is a sulphur or oxygen atom or a sulphinyl radical, R1 is any one of the C-3 substituents from antibacterially-active cephalosporins known in the art, R2 is a hydrogen atom or a 1-6C alkyl or 2-6C alkenyl radical, R3 is a hydrogen atom or one of a variety of radicals defined in the specification, and the pharmaceutically-acceptable acid- and base-addition salts thereof, characterized by reaction of a compound of the formula IX: <IMAGE> IX in which R16 and R17 individually have one of the values given above for R2 and R3, or a derivative thereof in which the carbonyl group is masked, with a compound of the formula X: <IMAGE> X in which R18 is a hydrogen atom or any one of the cephalosporin 3-carboxylic acid protecting groups known in the art; whereafter, when R18 is other than a hydrogen atom, the protecting group R18 is replaced by hydrogen by conventional means. |
